Re: Yanmar 1820D Tire Adjustment & PTO Question from Washington

Re: Yanmar 1820D Tire Adjustment & PTO Question from Washington

Have a look under the front of your seat. On mine there is a black wheel to adjust the rate of descent of the 3 point hitch. Turn it all the way anti clockwise should give you almost instant drop. If that doesn't work, I haven't a clue.

Re: Yanmar 1820D Tire Adjustment & PTO Question from Washington

There are likely two valves on that thing that affect drop rate.

Bluest described the 'service valve' under the front of the seat. This valve should be closed (clockwise) when you want the implement to stay up forever, engine running or no. It chokes the return line from the 3-point. 99% of the time this valve should be left wide open, counterclockwise.

The other valve to look for is the 'drop rate valve'. You adjust this one to get the desired drop rate, so that heavy implements don't come crashing down. This one's harder to find. Look for a tiny t-handle likely painted red. On some Yanmars it is halfway down the left side of the transmission under the left-rear of the seat. Adjust as needed.

Here's the drop rate valve shown the manual for an older Yanmar. There is red tubing slipped over the T (L, in this case) to make it more visible.

Re: Yanmar 1820D Tire Adjustment & PTO Question from Washington

Hi Rob,
I'm up in the Yelm area, just below Ft. Lewis. My 1820D will drop my 4 ft Howse Brush Hog in a matter of seconds. It must be a pressure adjustment issue. Tractor Ernie, just south of Portland, used to deal in used Yanmars and has a wealth of experience and knowledge about them. If lucky, he may weigh in on your question. Sorry I can't be of specific help on this issue. The PTO low speed, 540 rpm, is quite sufficient for the grass, weeds and brush I have to contend with.

Re: Yanmar 1820D Tire Adjustment & PTO Question from Washington

According to the parts mnaual I have for the 1820 it does not have the controls Californial has described. Rather, it has only the round knob under the seat that is called a slow/stop valve. It should be adjusted toward the closed position in order to control descent speed. Open it a little and your drop speed will increase. Yours may or may not have the looped hose shown there.